Internal combustion engine



June 1932- W. R. GRISWOLD 1,864,904

INTERNAL COMBUSTION ENGINE Original Filed March 5. 192 8 2 Sheets-Sheet 1 glww/ntoc WALTER H- Gmswuu:

June 28, 1932. w. R. GRISWOLD INTERNAL comsus'rxon ENGINE Original Filed March 5, 1928 2 Sheets-Sheet 2 I 3mm WALTER F2. ERISWDLD v 8] adapted to,'and has been described in connecft 12 is of that type in which the cranks 13 are headli ers-19oz B- GRISWOLD, O! DETIB'OIT,

incisions,- eonranr, or nn'nnoi'r, urea-11cm,

ASSIGNOB TO PACKARD MOTOR CAB A COBEOBATION OF MICHIGAN mrnnmln oonnusriou Enema 1 Application filed March 5,

This invention relates to internal combustion engines and art-icularly to means for damping torsiona vibration of the crank shafts of such engines. It is especially tion with an engine in which the crank sha has more than one crank between adjacent shaft bearings, so that there is a crank check:

or crank arm common to two cranks. 10 One of the objects of the invention is to pro vide effective means for damping torsional vibration in engine shafts which shall not increase any of theengine dimensions, part1cularly the overall length thereof.

Another object of the invention is to pro vide such damping means which .may be readily housed within the engine crank case, without necessitating changes in the mounting and arrangement of the drive for the en- 1 gine accessories and other connected elements,

. and without interference with existing engine Another object of the invention is to ro.

' damper which may 23 mounted on a cheek or arm of the crank shaft and which will not disturb the static or dynamic balance of the shaft.

Other-objects of the invention will appear from the following description taken: in connection with the drawings, which form a part of this specification, and in which: I Fig. 1 is a view, partially in side elevation and partially in longitudinal vertical section through part of an internal combustion engine embodying the invention; 1

Fi 2 is an end view of the double crank arm s owing the invention, partially in transverse section substantially onthe line 2- '-ofFig.-1;- a v Fig. 3 is a section substantially on the line 3--3ofFig.2,and, Fig. 4 is a view, similar to Fig. 2, showing a modified form of the invention.

Referring to the drawings, 10 represents a 1145 art of the crankcase of. an internal combus- P tion engine, being one ota number oitransverse webs therein. These webs supper suitable aligned bearings 11 for air-engine crank shaft 12, the latter having the usual 0 integraleranks 13 each of which is connected 1928, Serial in. 259,158; Senewed August as,

I be reduced in on the sides of the crank arm t is secured to its supporting member which passes bearing 28, and about which the inertia memby a connectingrod 14 with a piston mounted 1n one of the engine cylinders, the piston and cylinder not being shown in the drawings, but being ofusual construction. In the embodiment ofthe invention shown, the crank shaft 55 formed in pan'slbetween adjacent bearings 11, each pa r having a common crank arm or cheek 16, but it is to be understood that the invention is not limited to shafts of this type but may be applied to crank shafts having any of the well known arrangements of cranks and bearings.

The forward end of the crank shaft 12 may diameter and provided with a gear or sprocket l7, rotatably secured thereto as by a ke 18, through which the engine cam-v shaft an other engine accessories may be driven by an intermeshing gear or a sprocket cha n (not'shown). The gear 17 ma be conveniently retained in axial position y a nut 19 screwed to the reduced end 21 of the shaft andprovided with teeth 22, which, may be engaged with teeth on a suitable starter she not shown) I The damping means of this invention is illustrated as 'mountcd near the forward end of the crank shaft 12, on the crank arm 16 thereof. It is in the form'of a pair of weight or inertia members 23, arcuate in shape and preferably conforming incontour to the circle of rotation, which are pivotally mounted to oscillate in 4 The mounting the plane of rotation thereof. means may be of any suitable construction, butin the present embodiment it consists of a-pair of supporting members or plates 24,

2 rigidly secured to the sides of the arm as by bolts 26. Each of the plates 24 is provided with a integral lug or hinge member 2 which is bored to form a suite le pin bearing 28. Thishinge member 27, is disposed between a pair. of similar lugs'or members 29, integral withthe inertia member 23 and similarly rovided with holes 31 which are in line with 95 The inertia member23 24 by a of any suitable form, the holes 31 and the the bearing hole 28.

pivot or hinge pin 32 through ber may oscillate. The pin 32 may be retained in position in any convenient way, as

by a lock pin 33, which is threaded into the thereof and has a aring on the member 24 which is secured to the crankarm. These parts are referablyso designed that there is considera l'e friction 0r resistance to turning" between the pin-32 and the bearing 28.

vide seats'for a pair of compression springs 36, preferably of helical the plate 24,-and theymay be conveniently positioned thereon by'the heads of the retHIIllIlgbOltS 26, or the nuts thereof, which are disposed within their end turns, as clearly shown in Fig. 2. e springs 36 are spaced oscillatory displacement therefrom.

he combined pressure of the springs 36 is also exerted upon the inertiamember in such a way as toiurge it bodily away from the crank chcek'lfiu This greatly increases t e bearingpressure between the pin 32 and t e If desired, the bearing surface 28 may be lu'b ing plate24, which communicates through a passage 38 in the crank arm with the usual lubrication conduit 39 which isadapted to supply lubricant to the crankp' e operation of this device will be read.-

' ily understood from the above description.

form as shown. ese springs 36-seat at their other ends on 44.

as a hemispherical riqated from the engine lubricating sysd tem, by means of a passage 37 in the supportb reason of the connectlon provided b the Y it does not necessitate any because of their inertia. This causes the ei's to rock or oscillate upon the pivotal mountings 82 with respect to the cranh: which movement is opposed by the springs 36, which are alternately compressed, and also by the considerable friction in the pi;-

This fric- 5 and the disturbance is accordingly damped. In Fig. 4 is illustrated a modified form of is invention, in which one end of the pair of inert-1a members are dispensed with, a spacing member or strut being used to separate the adjacent enscof these members. In this construction the spring seatsB at one end of each of the inertia members are omitted, the member being provided with a g depression at the bottom his recess 45? is preferably of a recess 47.

threaded for the reception of a bushing 48 i in which a ball retaining member as is mounted. The 'spacingniember is formed with ball ends 51 which are adapted to seat in the sockets abfand are retained therein by the member 49, and this member 4 32 passes through suitable aligned openings 52 prosuppor ing be members 23 are pivotally mounted on the pins 32, as in the construction previously described, and are also provided with the springs 36, and it is evident, therefore, that the member 44 is maintained under compression by the expansive action of the springs, the reaction being taken at the bearing surface 28. It will also be evident that in this spacing member 4:4. Considerable friction is produced in this form of the device between the ball members 51 and their sockets or seats 46, which friction is added to the friction at the surface 28 and tends to in crease the effectiveness of the damper.

It will be seen that this invention provides a simple and effective vibration damper, which by reason of its mounting onthe en-= crease the length of other dimensions. Being locate on a crank cheek behind the first crank shaft bearing 11, change in the arrangement of the driving pinion 17 at the front end of the engine.

oreover, as'the inertia members are of equal mass and are symmetrically disposed the springs 36 at a ance of the crankshaft is not in any way each acts as a so that the baldisabout the axis of rotation, counterweight for the others,

turbed.

It will be understood that various forms of the invention other than those described above may be used without departing from the spirit or scope of the invention.

What is claimed and desired to be secured by Letters Patent, is

1. A vibration damper for crank shafts having its end cranks connected by a common arm, of balanced inertia members pivotally mounted on said arm to oscillate in the plane of rotation thereof, and means connecting said inertia members and the arm to increase the frictional resistance to oscillation in said mounting.

2. A vibration damper for crank shafts having a ertia members of substantially equal mass on opposite sides of said arm, pivotal means con necting each of the inertia members to the arm for oscillation thereon, and means to increase the friction at each of the pivots.

3. A vibration damper for crank shafts having a crank arm, comprising balanced inertia members pivotally mounted on said arm to oscillate in the plane of rotation thereof, and means including springs between each inertia member and the arm and aspacing member between the inertia members to increase the frictional resistance to turning of said pivotal means.

4. A vibration damper for crank shafts having a crank arm comprising pivot members symmetrically disposed about the axis of rotation of said shaft, and inertia members of substantially equal mass carried on said ivot members, said pivot members-having a substantial frictional resistance to oscillatory movements of the inertia members thereon.

-5. A vibration damper for crank shafts having a crank arm comprising supports secured to the crank arm having integral lugs provided with pivot bearin s, pivot pins mounted to oscillate against ictlon in said bearings, and inertia members of equal mass mounted on said pins and symmetrically disposed with respect to the axis of rotation of the crank shaft.

6. A vibration having a crank arm bers oppositely dis damper for crank shafts comprising pivot memosed on said crank arm, inertia members 0 substantially equal mass pivotally mounted on said ivot membe spring means between each inertia member and the arm at one side of the plane of the pivot members, and a spacing member connecting the inertia members on the other side of said plane.

7. In a vibration damper for a crankshaft havin a crank arm, the combination with a pair 0 inertia members of substantially e ual mass, of means for supporting said mem era crank arm comprising a pair of in-- on opposite sides of said crank arm for oscillato? movement with res ct thereto, and means or absorbing the osc1 atory energy of 7 said inertia members.

8. In a vibration damper for a crankshaft havin a crank arm, the combination with a. pair 0 inertia members of substantially equal mass, of means for supporting said members on opposite sides of sald crank arm for oscillatory movement with respect thereto, said means including resilient elements interposed between said crank arm and said members for yieldably resisting oscillatory movement of the latter.

9. In a vibration damper for a crankshaft having a crank arm, the combination with a. pair of inertia members of substantially equal mass, of means for supporting said members on opposite sides of said cran arm for oscillatory movement in the plane of the crank arm, said members being substantially symmetrical with respect to the axis of rotation of the shaft, and means for resisting and absorbing the ener of the oscillatory movement of said mem rs,

10. In a vibration damper for a crankshaft havin a crank arm, the combination with a pair 0% inertia members ofsubstantially equal mass of means for pivotally mount'mgi said members on opposite sides of the era arm so as to maintain the balance of the shaft and yieldable means interposed between each inertia member and the arm on each side of said means. I

In testimon whereof I afilx m signature.

. ViALTER R. GRI WOLD. 

